Pistorius, who has been nicknamed the "blade runner" for the carbon-fiber blades on which he runs, was accused today of killing his girlfriend, 30-year-old model Reeva Steenkamp. Pistorius allegedly shot Steenkamp several times at his home overnight in the South African capital of Pretoria.

The sprinter, who took home gold and silver medals at the London Paralympics in 2012, enjoyed firing guns and would often leave his home in the middle of the night to shoot at a nearby range, according to Daily Mail writer Jonathan McEvoy, who spent time at Pistorius' Silverwoods estate on the outskirts of Pretoria in 2011.

"He enjoyed shooting," McEvoy told ABCNews.com in a telephone interview from London. "There was a range nearby, and when he wasn't able to sleep in the night, he'd go there. He had a small gun by his bed, and a big gun by the window, some sort of machine gun."

Police Lt. Col. Katlego Mogale said a 9-mm pistol was recovered at the scene and a murder case opened against Pistorius, The Associated Press reported. The precise circumstances surrounding the incident are unclear. Local reports say he might have mistaken her for a burglar, according to the AP.

Although Pistorius' home, which McEvoy described as big for a young man living on his own, is heavily secured with his personal armed guards, Pistorius told McEvoy that he worried that the guards were working with potential burglars on invading his home.

"It's usually safe in guarded estates like this until that happens," McEvoy said Pistorius told him.

Gated communities are increasingly popular with the wealthy in South Africa, as well as the middle class. Guard dogs, electric fencing and complex security systems are designed to protect residents from threats from the outside world.

Pistorius' concerns about his personal safety in his home were similarly reflected in a January 2012 New York Times article, in which he described his reaction to a security alarm going off in his home. When the alarm triggered, he crept downstairs, gun in hand, only to find nothing, according to the Times report.

Crime, particularly violent crime, along with robberies and home invasions, is a significant issue across Pretoria and South Africa, which has one of the world's highest rates of violent crime. In 2011, the homicide rate was 31.8 per 100,000 people.

McEvoy said Pistorius had an unusually large arsenal.

"Even by the standards of a very scary area where he lived, it was unusual for him to have as much as that," he told ABCNews.com.

McEvoy described Pistorius as generally easy going and relaxed, but prone to drastic shifts in mood.

"On days his mood would swing the other way, and he could be very miserable and down, surly, and there was no reason to explain it," he said.

Police said they have heard reports of an argument or shouting at the apartment complex, and that the only two people on the premises were Steenkamp and Pistorius. Police also confirmed there have previously been incidents of a domestic nature at the home of Pistorius.

South African Sports journalist Lelo Mzaca refuted rumors that Pistorius was anti-female in an interview today with ABC News.

"There have been rumors about him not being a nice person, and not having a good track record as far as some girlfriends are concerned," he said. "I've never encountered that side of Oscar Pistorius, because every time I've met the man, he's been an absolute gentleman."

A spokesperson for Pistorius at Fast Track in London said Pistorius is "assisting the police with their investigation, but there will be no further comment until matters become clearer."

The National Prosecuting Authority (NPA) said a court hearing for Pistorius, who is in jail, will be Friday at 9 a.m. local time.

Pistorius, a sprinter, had double below-the-knee amputations and a part of his legs has been replaced with carbon fiber blades. In 2012, he became the first double-leg amputee to participate in the Olympics, competing in the men's 400-meter race.

Steenkamp, according to her Twitter bio, is a law graduate and model. She tweeted Wednesday, "What do you have up your sleeve for your love tomorrow??? #getexcited #ValentinesDay." She recently appeared on the cover of FHM magazine, in commercials and was due to appear on a reality-TV show, "Tropika Island of Treasure."